Leber's hereditary optic neuropathy is a maternally transmitted disease resulting from a point mutation in mitochondrial (mt) DNA. In this report we describe a case of Leber's disease with typical clinical findings but atypical ophthalmoscopic presentation. A 14-year-old boy developed severe loss of vision acuity in the left eye, with only partial recovery, followed 4 months later by the same symptoms in the right eye. Fundoscopic examination showed hyperemic papilla on the right eye and optic disc pallor on the left eye. Polymerase chain reaction analysis of lymphocytic mt-DNA revealed a point mutation at 11778. Leber's disease should be considered in young patients (not always male) with sudden visual loss and simple papillary involvement at fundoscopic examination but without the typical telangiectatic microangiopathy.